19612421 has 2 divisors, whose sum is σ = 19612422. Its totient is φ = 19612420.

The previous prime is 19612409. The next prime is 19612447. The reversal of 19612421 is 12421691.

It is an a-pointer prime, because the next prime (19612447) can be obtained adding 19612421 to its sum of digits (26).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 13432225 + 6180196 = 3665^2 + 2486^2 .

It is an emirp because it is prime and its reverse (12421691) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 19612421 - 2¹⁸ = 19350277 is a prime.

It is a Chen prime.

It is equal to p_1247462 and since 19612421 and 1247462 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (19612471) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9806210 + 9806211.

It is an arithmetic number, because the mean of its divisors is an integer number (9806211).

Almost surely, 2^19612421 is an apocalyptic number.

It is an amenable number.

19612421 is a deficient number, since it is larger than the sum of its proper divisors (1).

19612421 is an equidigital number, since it uses as much as digits as its factorization.

19612421 is an evil number, because the sum of its binary digits is even.

The product of its digits is 864, while the sum is 26.

The square root of 19612421 is about 4428.5913110153. The cubic root of 19612421 is about 269.6768928723.

The spelling of 19612421 in words is "nineteen million, six hundred twelve thousand, four hundred twenty-one".